CCL2 and infection: While no other notable vitamin D3 treatment effects were observed for other cytokines investigated (IL-17A, IL-36RA, MCP-1, and TNF-α), infection status did result in measurable differences, with clinical cows secreting higher levels of IL-17A (Figure 7D; P < 0.05) and TNF-α (Figure 7F; P < 0.001) compared to the subclinical and noninfected control groups.